You are right, Pool Doc....even showers are problematic when the asthma is flaring. We are looking for solutions to avoid triggers, hospitalizations and so on. While the pool isn't perfect this year, its the first summer in 5 years without a trip to the ER. I'm not on this site looking for medical advise. I appreciate the input from the person who quoted the study on Nature 2 sanitation since we need a pool that is safe for everyone to use. I appreciate the information on Baquacil and Softswim. One thing I've learned since owning a pool is that everyone is very opinionated about how to properly maintain a pool, but no body agrees on the process.